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Mira STATES "r lFFICEQ ERNEST BETZ, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OF ONE- I-IALF TO GEORGE E. HUIGHINS, OF SAME PLACE.

COWL.

SPECIFICATION forming part of Letters Patent No. 391,503, dated October 23, 1888.

Application filed July14,1888. Serial No. 279,913. (No model.)

To all whom it may concern.-

Be it known that I,- ERNEST BETZ, of Washlngton, in the District of Columbia, have invented certain Improvements in Cowls for Chimneys, of which the following is a specification.

The object of this invention is to provide a s1mple cap without moving parts by which upward suction may be introduced within the chlmncy whenever the-external air is in motion, and which will effectually prevent, under all circumstances, down currents from the outside.

In the accompanying drawings, Figure 1 is a perspective view of my improved cap. Fig. 2 1s a vertical central section of the same on the line as m of Fig. 1. Fig. 3 is a horizontal section on the line y y, Fig. 2, looking upward.

Iu constructing my cap I provide an upright cylindrical .pipe, A, of any suitable diameter, and give the upper end or mouth of the same an inward taper or contraction, as shown at a, so that its extreme upper end or outlet is of smaller diameter than its body. Through the walls of this pipe, at the upper end or below the contracted mouth, I form a series of vertical slots or openings, b. Outside of and opposite each of these openings, at a distance of two inches (more or less) therefrom, I secure the upright flat arms or deflectors B, the extremities of which are bent inward and riveted or otherwise firmly attached to the top below the ends or openings. These arms stand, as shown, in such relation to each other and to the openings that they serve as guards to prevent the air-currents from passing into the openings from the outside. They also serve to deflect the currents of air past the openings in such manner as to produce an outward draft or suction therethrough and a consequent upward current-through the pipe.

It is to be particularly noted that the cap is constructed without a flange-collar or other surface to sustain the lower ends of the de flectors, these flanges, which are commonly used in other caps, being objectionable for the reason that they frequently tend to deflect the passing air into the openings. Within the upper end of the pipe, immediately above the upper ends of the openings 6, and at the lower part of the contracted portion, I secure a central plate or diaphragm, O; of a diameter slightly less than that of the pipe, so that an annular space is left between the periphery of this plate and the inner surface of the pipe in immediate proximity to the upper ends of the openings b. Above the upper end of the pipe, at a distance of three inches (more or less) therefrom, I fix rigidly a cap or cover, D, preferably in the form of a hollow cone, as shown.

Around the mouth of the pipeI commonly secure rigidly a collar, 0, the upper end of which is of tapered or conical form, and which is flat on the upper side. This is not a necessary but it is a desirable feature of my struct ure. I commonly support the top or cap D by legs d, secured to the flange c, as shown.

It is to be observed that in my cap the plate 0 is below or within the end of the pipe, and that it is of a diameter substantially equal to or greater than the mouth or delivery end of the pipe.

The operation of the device is as follows:

The horizontally-moving currents of air, being deflected by the arms B and prevented from entering the openings, act, as before mentioned, to induce an upward suction through the pipe. They also serve, in passing beneath the cap D and over the contracted mouth of the pipe, to produce a suction upward around the upper edge of the baffle-plate 0. If at any time air chances to be driven downward into the mouth of the pipe A, it will encounter the plate C, by which its direct downward course is prevented and the air directed outward toward the edges of the plate. If driven downward past the edges, the air escapes in a thin annular current in direct proximity to the upper ends of the openings B, through which there is a strong outward draft, and through which the air is therefore carried. This last named action is due to the fact that the plate 0 is located at or near the upper ends of the openings b, and that the outside arms or deflectors, B, are employed to cause a constant outward suction through the openings.

Having thus described my invention, what I claim is-- 1. In a chimney-cap, the pipe A, having the contracted upper end or mouth a and. the lateral openings Z), in combination with the baffie-plate 0, located in said pipe at or near the upper ends of said openings, the cap or cover I), located immediately above the pipe, and

the external deflectors, B, as described and shown.

2. A chimney-cap containing, in combination, the following elements: the vertical pipe A, having the contracted upper end and the vertical slits or openings 1), the external arms or deflectors arranged opposite said openings and attached at their ends directly to the pipe, the external collar, 0, the baffle-plate O, located within the pipe, and the dished plate D.

3. In a chimney-cap, the vertical pipe having lateral openings 12 and external deflectors, B, as shown, in combination with a baflieplate, 0, located within the pipe below its up per end and adjacent to the upper ends of the lateral openings, whereby air descending the pipe is compelled to pass over the edges of the plate and outward through the openings.

In testimony whereof I hereunto set my hand, this 3d day of July, 1888, in the presence 0f 20 two attesting Witnesses.

ERNEST BETZ.

Witnesses:

P. T. DODGE, W. R. KENNEDY. 

